I have a TZT9 whose software is way out of date. It does not need a full OS update. I have followed the directions on the website. I have booted 2 different SD cards. When I put the SD card in the unit and start it up....it says bootmgr missing in the upper left hand corner. It also says press "control Alt Delete to exit" I see the bootmgr on the SD card and the download. Of course it is Sunday and Furuno is not open. Any direction would be greatly appreciated. :angry